The improperly formatted number you highlighted was from the cart itself. It was not the issue. The issue with paypal was at the bottom: "CancelURL is invalid."
You need to use a full URL for the cancel url. The wizard tries to get that from your site definition when it runs, but maybe you didn't have a remote site defined at the time you ran the wizard since it only had the page name. I've updated it using the FTP information you provided previously and I think it is working now when you use the paypal checkout option.